1. Field of Invention
This invention relates to phase-reversible compositions for use in the manufacture of adhesives, fire extinguishing agents, viscosity control agents, tackifiers, coating agents, dye assitants and the like. The compositions under contemplation are reversible in the phase between liquid at a low temperature and solid at a high temperature, and having excellent compatibility and surface-active properties.
2. Prior Art
Known as such phase-reversible compositions are, for example, methylcellulose and polyoxyethylene solution of water, both being liquid at a low temperature due to hydration of their hydrophillic groups and solid at elevated temperature due to a decrease in the hydration effects. These high molecular materials have a common drawback in that they tend to release therefrom free water when changing into a solid phase at increased temperature, and hence prolonged length of time is required to bring them back into a liquid state similar to that which has existed prior to the heating.
With a view to eliminating or alleviating the above-noted drawback of the prior art compositions, the present inventors have previously developed and introduced certain improved compositions as disclosed in copending U.S. patent application Ser. No. 624,225, now U.S. Pat. No. 4,072,646 the compositions of which essentially comprise (1) high-molecular anions resulting from the dissociation of the carboxylic group of a conjugated dienemaleic acid derivative copolymer, (2) alkali metal cations or ammonium cations, (3) magnesium ions, (4) anions which form water-soluble magnesium compounds with Mg.sup.++, and (5) water. The compositions of the copending patent application were reversible between liquid and solid at increased rate of speed and in addition, were extremely easy to control their viscosity at low temperature and their gel strength at high temperature. For these advantages, the prior compositions of the present inventors have been found useful in the preparation of fire extinguishing agents, textile printing materials, glues, viscosity-control agents, water-soluble quenching media and the like. However, it was later found that the prior compositions are not completely satisfactory in their compatibility with other water-soluble organic materials and furthermore somewhat poor in their surface-active properties such as foaming ability, dispersability and emulsifiability.